As in other areas of physics, the real experiment plays an important role also in teaching of nuclear physics. Nowadays various safe sources of ionizing radiation and the corresponding detectors are available and allow us to make simple and conclusive experiments in the field of nuclear physics at all types of schools.
The paper discusses the influence of background radiation on the interpretation of results from school measurements with weak radiation sources. The paper also shows several examples of experiments demonstrating the fundamental phenomena of nuclear physics such as the existence of radiation from natural or artificial sources (including objects around us), shielding of the radiation using different materials, some properties of gamma radiation, basic ways to protect against radiation and other.